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F. J. LEISEN AND E. S. DUNN.

TUNNEL KILN. APPLICATION FILED IAN.,3I. Isls.

Patented July 6, 1926.

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Patented July 6,1920.

TUNNEL KILN.

F.1. LEISEN'AND E. s. DUNN.

APPLICATION FILED IAN.3I.. I.9I9. L,

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APPucATmN man 1AN.31. 1919.

Patented J uly 6, 1920.

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FRANCIS JOSEPH LEISEN, OF METUCHEN, NEW JERSEY, AND EDVIN S. DUNN, OF IIUNTINGTON, WEST VIRGINIA.

TUNNEL-Kinn.

Specification of Letters Patent.

Application med January 31, 1919. serial No. 274,319.

To all wlw/a t may concern Be it known that we, FRANoIs JosErH LnisnN and EDWIN S. DUNN, citizens of the United States, and residents of Metuchen, in the county of Middlesex and State of New Jersey, and Huntington, in the county of Cabell and State of West Virginia, respectively, have made certainnew and useful Improvements in Tunnel-Kilns, of which the following is a specification.

Our invention relates generally to kilns, and more particularly to that type of kiln known as a tunnel kiln, wherein the articles to be burnt, irrespective of their particular nature, are mounted or supported upon movable carriers, these carriers being intermittently advanced through the kiln at regular periods, and in a continuous line, so that each carrier with its load enters one end of the tunnel of the kiln with dried material thereon, and emerges from the opposide end of the tunnel with the burnt articles, having been subjected to various degrees of dryingand burning heat, and then to cooling drafts, so that upon emerging from the kiln, the articles are burnt and have been cooled to an extent permitting of their rehandling in order to avoid the necessity for the great storage spaces kilns of this character now require.

Our invention is directed in particular to a novel arrangement of the parts of the kiln, so as to bring about greatly increased eifectiveness in the speed of operation, as well as a greatly increased efficiency, and

proposes not only a rearrangement as regards the ordinarily constructed kiln of this type, but certain new features of a nature calculated to efficiently cooperate with the rearranged form.

In the accompanying drawing forming our present improvements Figure 1 is a side elevation of our improved kiln complete;

Fig. 2 is a horizontalsection taken lengthwise through the kiln structure, and of a more or less diagrammatic nature, having the various attachments removed;

Fig. 3 is a transverse vertical section taken substantially on line 3 3 of Fig. 1;

Fig. 4 is a similar view taken substantially on linev -t of Fig. 1;

Fig. 5 is another similar view taken subA stantially on line 5&5 of Fig. l;

Fig. 6 is another similar view taken substantially on line 6-6 of Fig. 1;

Fig.V 7 is a front elevation of one of the fire zones, and,

Fig. 8 is a section through one of the fire zones taken parallel to its front wall.

Referring now to these figures, our invention relates to that type of kiln which embodies an elongated tunnel generally indicated at 10, the entrance end 11 and the eXit end 12 being in practice normally closed by somewhat similar doors, opening of which respectively permits of the introduction and removal of material. lool air is admitted to the exit end of the tunnel through Ventilating doors 12a, as will be more fully described hereinafter.

In the present instance, the kiln tunnel 10 has a covering arch 13 between the upper portions of its side walls 14C, as best seen in Fig. 5, these side walls 1a being built up wardly upon what is preferably a solid masonry foundation 15, at opposite sides of a trough in the foundation through which rails 16 are led.

In the formation of the foundation, its upper surface, longitudinally alongside the walls 14C, is formed with grooves 15 into which the lower ends of the buck-staves 17 are disposed at any desired points, and by virtue of which grooves the buck staves may be variously spaced more or less in accordance with the thickness of the walls 14. rlhe upper ends of these buck staves are connected as usual by rods 18, and turn buckles 19, and the inner surfaces of the walls 1li above the foundation 15 are formed with longitudinal side grooves 20, into which the side edges of the platform 21 of the article supports in the nature of trucks extend, these trucks having wheels 22, which roll upon the tracks 16, and movement of which from the entrance end 11 of the kiln tunnel to its exit end 12 is facilitated by virtue of a slight declination of the entire tunnel from end to end, as indi- Patented July 6, 1220.

side walls 14 of the kiln tunnel have openings 26, as seen particularly in Fig. il, which openings,vit will be noted, are above the level. or the grooves 20k of the sidewalls,

so that the heat thrown into the tunnel from.

each lire zone will emerge therein at a point above the cars supporting the articles to the lower portions ofthe cars, that is, the

trucks and wheels, are protected from the `intense heat, and with Jfront and rear ends of cars in abutting relation entirely throughout the length of the kiln tunnel, it is obvious that the space below the car platforms may be made a cooling channel from end to end oi' the kiln.

Yt is also obvious 'from the foregoing vdescription that in operation, each car with its dried products Jfor burning, is thrown into the influence successively oi the fire Zones 23, 24 and 25, the zone 23 being for instance 1500 degrees Fahrenheit, the Zone 24;, 2000 degrees Fahrenheit, and the Zone 25, 2500 degrees Fahrenheit, thus increasing the heat in the direction of progressive movement of the cars through the kiln, which is brought about not only by the increase of heat at the lire zones,'but which is permitted by virtue of the disposition oi" theistack 28 at a point between the ire Zone 25 and the eXit end l2 on the tunnel, so that the zone 25 is nearest the stack and the latter draws the prodY ucts o' combustion and the heat from each of the lire Zones in the direction of movement oi' the cars through the kiln.

rThe stack 28 as seen in Fig. 3, has its opening controlled by a damper 29, and is arranged at one side of the tunnel 10 with its opening in communication therewith through an opening 30, and is disposed at the relatively opposite side of the* tunnel with respect to a chamber 3l built at one side of the tunnel, and in communication with the tunnel opening through on opening 32, this chamber 3l having an upwardly extending pipe 33 leading therefrom and communicating with the stack opening through an open-v ing 34 controlled by a damper 35. This pipe 33 also communicates with a pipe '36 extending forwardly above the'kiln and communicating at its forward end with a fan casingy 37, the fan within which sucks through the pipe 36 and discharges into a pipe 38, projecting forwardly from the Jfan casing 37 and in turn communicating with branch pipes 39, which enteropposite sides of the kiln, through its side walls 14 as seen particularly in Fig. 6, these branch'pipes'-BS) being le;y into the kiln ata suitable'v point between its entrance end 1l and the first tire zone'23 of lowest heat.

Thus in operation, the' cars with their dry products are pushed into the entrance ll of the kiln and proceed under moderate heat which gradually raises their temperature until they reach a point opposite the branch pipes 39 when they are subjected to Vthe lowest degree oit' heat of the kiln. The material is then subject to this same heat untilv it arrives at the first iirezone 23, and bearing in mind that the cars are movedV intermittently at regular intervals, and that each car remains stationary during an interval between movements, at each olf the lire Zones 23, 24: and 25, it is obvious that each of these tire zones isrin length equal to the length of From this fact it is further obvious that the spaces between the fire zones will be' equal to the lengths of two cars, as shown in Fig. 2, so thatr each car will Vbe subjected iirs't to the heat of the fire Zone 23until during successive movements it arrives opposite the ire Zone 2li, and that it will then be subjected to the heat of the Alire Zone 24 until during successive movements it arrives opposite the fire zone 25. It is furthermore obvious that it will be subjected to the heat of the tire zone 25 until after it has passed the stack 28, and that up to the time it arrives opposite the stack it has been continu. ously subjected to increasing degrees of heat flowing through the tunnel of the kiln in the direction of its travel through the kiln.

rIlhe stack 28 disposed between the series of tire zones and the eXit end ofthe kilns obviously brings the foregoing about, and likewise draws cooling air from the exit end l2 of the kiln through the Ventilating doors 12a, so that as each car passes the stack 28 it is at once subjected to this cooling dra-ft which becomes of course cooler as the car approaches the exit end l2. The cool airl which enters the tunnel through the ventilating doors l2fL is of course heated during its passage to the stack where it may be conducted to a drying kiln or'utilizing this heat, which is ordinarily wasted, to eilect a drying of the ware before it is introduced to the tunnel kiln.

Through the kiln constructed as above, we obtain maximum efficiency 'from the heat utilized in the operation and much greater efficiency through the relative arrangement of the parts as proposed than it is possible to accomplish with the usual tunnel Vkiln where the heat products flow in a direction opposite to that of the movement of the products through the tunnel.

Our improved arrangement enables Vus to readily cut out one of the fire Zones if foundv expedient Vin connection withy the burning of certain classes of ware, and permits 'of a much speedier operation and reduction in the time intervals between movements of the ware in the kiln and consequently a very material reduction in the time of the passage of ware completely through the kiln.

As shown in Fig. 8, the stack 28 may communicate at its lower end by a side opening 40 with a boiler 4l in turn communicating with the upper portion of the stack through 'a pipe 42 having a damper 45 and in this and in other ways, certain of which we will now mention, we may take advantage of the ordinarily wasted heat products, and turn the same to useful purposes.

For instance, steam pipes 44 may be eX- tended longitudinally through the upper portions of the tunnel walls-14 at the sides of the arch 13, these points being' the points of greatest heat, so that the steam generated in these pipes may be transported for use at otherl points, and Aconnection with various apparatus,

The several lire zones Q3, 24 and 25 may utilize various fuels for instance coal, oil and gas, and if gas is utilized, particularly natural gas, the pipes 44 may be utilized to preheat the gas, as preheated gas is capable of, much more economical use than if unheated. ln the pipes 44 the gas may be preheated to a very high degree, there beingk no danger of combustion until the gas is mixed with air at the burners, one of which is seen at 45 in Fig. 7 and to which the is led from the pipes 44 through branch pipes 46.

ln connection with either fuel it will be noted that the outer Yfire openings 47 of the fire zones are located at the lower portions of the outer walls 48 of these lire zones and upon horizontal planes below the plane of the. openings 26 of the tunnel walls through which the heat products lind their way into the interior of the tunnel so that the heat, as before stated, strikes the bridge walls 27, and is thereby given a greater tendency toward upward movement than would otherwise be present.

lhen it is desired to utilize a portion of the heat within the kiln for heating the water within the boiler 4l., the dampers 35 and 45 are opened and the damper 29 closed thereby causing the heat from the kiln to traverse the pipe 33, the opening 34 and downwardly within the stack 28 and beneath the boiler 4l. through the opening 40. The heat passes around the boiler 4l and upwardly into the stack 28 through the pipe 42.

We claim 1. A kiln of the character described having a tunnel through which material to be burnt is intermittently moved from end to end, a series of lire zones spaced apart and introducing in the length of the kiln and communicating at separate pointsv with the tunnel thereof, and intermediate the ends of the latter, and a stack communicating with the tunnel at a point between the series of lire zones and the enit end of the tunnel whereby to draw the heat products from the fire zones in the direction of movement of material through the tunnel from its entrance to its exit.

2. A kiln having a tunnel provided with an'entrance at one end and an exit at its opposite end, lire zones communicating with the tunnel at separate points in the length of the kiln, and stack in connection with the tunnel between the several fire zones and the exit end of the tunnel, as described.

A kiln having a tunnel provided with an entrance at one end and an exit at its opposite end, fire zones communicating with 1iate the ends of the kiln,

the tunnel intermeu i stack in communication with the tunnel at one side ot the several tire zones, and means for' wftluliavlfing products from the stack same intothe tunnel at the relatively opposite side of the several fire zones.

4. A kiln having a tunnel provided with an entrance at one end and an exit at its opposite end, fire zones con'imunicating with the tunnel at separate points in the length. of the kiln, a stack in connection with the tunnel between the several fire zones and the exit end of the tunnel, and means for withdrawing products from the stack and introducing the same into the tunnel at a point between the fire zones and the entrance ond of the tunnel.

y5. A kiln having a tunnel provided with an entrance at one end and an exit at its opposite end, a series of lire zones spaced apart lengthwise of the kiln and separately communicating with the tunnel, a stack in communication with the` ltunnel between the exit end thereof and the several lire zones, and means for withdrawing heat products from the tunnel adjacent to the stack and introducing the same into the tunnel between the entrance end thereof and the several lire zones 6. A kiln having a tunnel provided with an entrance at one end and an exit at its opposite end, a series of fire zones spaced the apart lengthwise of the kiln and separatelyl coi'nmunicating with the tunnel, a stack in communication with the tunnel between the exit end thereof and the several fire zones, means for withdrawing heat products from the tunnel adjacent to the stack and introducing the same into the tunnel between the entrance end thereof and the several fire zones, and the said last named means having connection with the stack to withdraw products from the latter.

7. A kiln having a tunnel provided with an entrance at one end and an exit at its Y tween the several fire Zones and the exitVV opposite end, a series of fire Zones separately communicating with the vtunnel at pointsl intermediate the said ends, a stack in communication with the tunnel at a point between the Yseveral lire Zones and the eXit end of the tunnel, an air chamber in communication with the tunnel adjacent the stack, a pipe leading along the kiln from lthe said air chamber, a second pipe having intermediate the said ends, a stack in communication with the tunnel at a point beend of the tunnel, an air chamber in communication ywith lthe tunnel adjacent the stack, a pipe leading along the kiln from the said air chamber, a second pipe having branches'let into the tunnel at points between the entrance end of the tunnel and the said lire zones, a fan for creating suction through the first named pipe and arranged to deliver into the second pipe, said first named pipe having connection with the stack, as described.

9. A kiln having a tunnel provided with an entrance at one end and an exit at the other, fire zones communicating with theA tunnel, and means for creating a draft in the tunnel so that the products of the fire zonesmove in the direction of the eXit end of the tunnel. Y

10. A kiln having a tunnel provided with an entrance at one end and an exit at the other, lire zones communicating with the tunnel, a pipe in circuit communication with the tunnel at points in the front and rear of the fire zones, and means for creating a draft in the pipe and tunnel so that the products of the fire zones move through the tunnel in the direction of the exit end thereof.

11. A kiln having a tunnel provided with the tunnel so that the products of the re Zones move inthe direction of the eXit end of the tunnel. Y

l2. A kiln comprising a ltunnel through which material to be burned is adapted to Y be moved in one direction, means for generatingfheat within the tunnel, and ,means for forcing the heat in the same. direction as the material is moved. Y

13. A kiln comprising a tunnel through Vwhich material to be burned is 'adapted to be moved in one direction, means for generating heat within the tunnel, and means foi" forcing the heat in the same direction as the material is moved for a portion of the length ofthe tunnel and returning part of the products of combustion to a point in advance of they heat generating means. Y

14k. A kiln comprising a tunnel through which material to be burned is adapted Vto be moved in one direction, means for generating heat within the tunnel of intensities progressively increasing in the direction in which the material is moving, and means for forcing the' heat in the samev direction Vas the material is moved.

15. A kiln comprising a tunnel through.

which material to be burned is adapted to be moved in one direction, means for generating heat within Vthe tunnel of intensities progressively increasing in the direction in which the material is moved, and means for forcing the heat in the same Vdirection as the material is moved for a portion of the length of the tunnel and returning part of the products of vcombustion to a point inr advance of .the heat generating means.-

FRANCIS JOSEPH' LESEN. EDWIN S. DUNN. Vilitnesses to signature of F. J. Leisen'): DANIEL D. LA FARGE, l/VILLIAM GALLAGr-IER. Vlll/witnesses to signature of Dunn:

WM. MARTIN, R. S. DOTHAT.

Edwin i... 

